feat(t/evaluator/evaluate-oom): comment intentions

t/evaluator/evaluate-oom-job.t

@@ -4,6 +4,10 @@ use Setup;
 use Test2::V0;
 use Hydra::Helper::Exec;
 
+# Ensure that `systemd-run` is
+# - Available in the PATH/envionment
+# - Accessable to the user executing it
+# - Capable of using the command switches we use in our test
 my $sd_res;
 eval {
   ($sd_res) = captureStdoutStderr(3, (
@@ -17,12 +21,21 @@ eval {
     "true"
   ));
 } or do {
+  # The command failed to execute, likely because `systemd-run` is not present
+  # in `PATH`
   skip_all("`systemd-run` failed when invoked in this environment");
 };
-if ($sd_res != 0) { skip_all("`systemd-run` returned non-zero when executing `true` (expected 0)"); }
+if ($sd_res != 0) {
+  # `systemd-run` executed but `sytemd-run` failed to call `true` and return
+  # successfully
+  skip_all("`systemd-run` returned non-zero when executing `true` (expected 0)");
+}
 
 my $ctx = test_context();
 
+# Contain the memory usage to 25 MegaBytes using `systemd-run`
+# Run `hydra-eval-jobs` on test job that will purposefully consume all memory
+# available
 my ($res, $stdout, $stderr) = captureStdoutStderr(60, (
   "systemd-run",
     "--user",
@@ -41,6 +54,8 @@ isnt($res, 0, "`hydra-eval-jobs` exits non-zero");
 ok(utf8::decode($stderr), "Stderr output is UTF8-clean");
 like(
   $stderr,
+  # Assert error log contains messages added in PR
+  # https://github.com/NixOS/hydra/pull/1203
   qr/^child process \(\d+?\) killed by signal=9$/m,
   "The stderr record includes a relevant error message"
 );